this thing came on out above south moutain were the comercial aircraft fly down the coridor for final aproch into salt lake it went strate up then down then side to side i have never seen anything fly like that then it stayed in one place my wife thoght it was a star tell it started moving agian and changing color it changed from flurecent purple to a light blue i have never seen before to red to a fire ornge to white like a star when it went to purple it lit the sky up like a wave coming at us the pilots flying have to of seen this thing it actuly chased a plane like it was a toy with speed i can only imagine would kill a human bieing it is very disturbing to me it is beyond my comprhension how that thing was flying great distances in a split second it was in one part of the sky the light went out then came back on clear over in onther part of the sky like 1000 times faster then any f-16 from hill airforce base could go and no noise thats it i guess just freaks me out must be using elctro magnetics hence lighting the particals up in the sky it has happined 4 times in the last year